Calendar.



No. 801,112. PATENTED OCT. 3, 1905. I'. SGHWBRDTFEGER.

CALENDAR.

APPLIOATION FILED MAY 19, 1905.

attenua# 1 Tr 1 /h X M, n x m x n UNTTED STATES PATENT CFFTCF.

CALENDAR.

Specification of Letters Patent.

Patented Oct. 3, 1905.

Application filed May 19, 1905. Serial No. 261,281.

To @ZZ whom it may concern:

Beit known that I, FELIX SCHWERDTFEGER, a subject of the German Emperor, residing at Posen, Germany, have invented new and usetul Improvements in Calendars, of which the following is a specification.

The object of my invention is to provide a simple, cheap, and convenient perpetual calendar which is applica-ble to a pen, pencil, or other like object and is readily adjustable to determine the day of the week oi' any given date in a series of years.

The preferred embodiment ot' the invention is illustrated in the accompanying drawings, in which- Figure 1 is a plan view of the calendar applied toa pen or pencil. Fig'. 2 is a plan view ot' the calendar-section forming' the inner stationary cylinder. Figs. 3 and 4 are similar views of the calendar-sections composing' the two outer cylinders, and Fig. 5 is a cross-seetion taken on line 5 5 of Fig'. 1.

The calendar comprises three parts or seetions A, B, and C, which may be mounted upon a pen, pencil, or other suitable supporting object D. The part A consists of a tablet or strip ot' iiexible material rolled into cylindrical form and suitably secured to the periphery of the support D. The upper portion of this part A is ruled to provide transverse and longitudinal columns a o, forming blocks or spaces ai, which with certain exceptions contain the suflix or terminal numerals of the years, beginning in the present instance with H00 and ending with "27, thus covering a corresponding term ot' years. The numerals extend transversely from left to right in columns of six in regular order, and some ot' the blocks are left blank or dotted, as shown, according' to the requirements of the system of calculation, while those blocks carryingl the numerals ot' leapyears are designated by hatching or suitably coloring them. A table A is thus produced, which for convenience ot' description may be termed a sutlix year-table.

At the bottom ot' the strip A is a monthtable A2, having blocked longitudinal and transverse columns t3 a* similar to the table A, the names ot' the months being irregularly arranged in certain ot' the blocks in a desired manner, while the blocks which are unoccupied by month-names are left blank or crossed out by an or cross-mark. 1t will be observed that the month-names ".Jan. and

Feb are duplicated, the duplicate names being disposed in the hatched or colored spaces a5 and properly arranged to be used when the year on which the calculation is based is a leap-year.

The part B comprises a cylindrical strip which surrounds the table A and is used in conjunction therewith. 1t is provided in its upper portion with a longitudinal observation-slot I), at one side of which is a table L' containing the prelix year of the current eentury--to wit, "19-and below which is a transverse table Z22 containing the names ot' the days of the week.

The part C consists of a cylindrical strip similar to the strip B and surrounds the lower portion of the cylinder A. In the lower portion ot' this part C is a longitudinal slot c and above the same a table C', ruled to form blocked transverse and longitudinal columns c and o2, containing the numerals 1 to 31,inclusive,designatingdays ot themonth. The transverse columns o extend obliquely, so that the numerals therein will be arranged spirally about the supporting object D when the part C is applied thereto, as shown in Fig. 1.

The part or cylinder A is stationary on the support D, as above described, while the cylinders B and C are revoluble,so that they may be adjusted tol make the desired calculations.

The mode of using the calendar' is as follows: 1f it be desired, for instance, to determine on what day ot' the week March 4, 1904, fell, the cylinder B is turned until the year suttix 04 on the table A is exposed through the slot I) and the cylinder C turned until the abbreviation Mar. in the table A2 is exposed through its slot c, whence it will be apparent, as the slots and c then register with the word Friday in the table t2, that March 4, 1904, fell on that day of the week. All the remaining dates of the month ot' March will then stand under the proper week-day names. 1n addition to the abbreviation Mar.7 the slot c will also expose the abbreviations for the months February and November, which in ordinary years have the same distribution otl days as March. As 1904 is a leap-year, however, the

exposed abbreviation "Feb. in the plain block or space will not indicate the true distribution of days in February for that year, the month-names in the spaces a being used in making calculations for January and Feb-V ruary for this and all other years which are leap-years. This being understood, the mode of adjusting' the calendar for making any calculation within the period covered by the calendar will be apparent.

The calendar, as shown, covers a period of twenty-eight years, and is therefore practically perpetual. since it is simply necessary at the end of each period to change the year-numbers of the part A to accord with the new relations between the months and years, which Change every twenty-eight years,

Having thus described the invention, what is claimed as new is"- l. A 'alendar comprising three members, one of the members having a year-suffix table and a month-table, the second member having a week-day table, a year-prefix table and an observation-slot alongside the latter table, said second member being' adjustable to cooperate with the'year-suilix table on the first-named member, and a third member having a monthday table and an observation-slot and adjustable so as to adapt the slot to cooperate with the month-table on the first-named member, substantially as described.

2. A calendar comprising three members, one of the members being provided with a year-snlix table having suitable designations r'or the leap-years, and a month-table having duplications for the iirst two months for leapyear use, the second member having a weekday table, a year-prelix table and an observation-slot alongside the latter table, said second member being adjustable to cooperate with the year-sntlix table on the first-named member, and a third member having a month-day table and an observation-slot and adjustable so as to adapt the slot to coopera-te with the monthtable on the first-named member, substantially as described.

In testimony whereof 1 aflix in y si gnature in presence ot' two witnesses.

FELIX senwnaprirne-nn. [1.. a] lVitnesses:

(Jl-UsTAv WTALLOR, THnoD. Hmm. LANGE. 

